Does the GT31 automatically save your session to the card or do you have to manually save after each session.

As Andrew says Sue, depends on your configuration.
Card should be set to "card size" and 1 sec sbn logging. logger should be set to 1sec sbp.
When turned on you should see a message, "card found" then, "new file". The card starts a new file every time the unit is turned on or off. The internal logger is continuous, it drops the oldest data as new data comes in, holds roughly 7 hrs.

You don't need to have anything to do with the internal logger, if it's logging to card OK. Even if the log to card fails, and you have to do a "save to card" it's not too hard to separate the multiple sessions on it. But it's not hard to clear the internal logger, and that means it will only have one session on it, depends how lazy you are. It's a long time ago, but I don't think I ever bothered, as I always used the SBN file from the card.
If you've already deleted it, there's nothing there to delete, unless you've turned the device on inbetween times

yes you need to delete the display so you don't get old stuff on the screen.
It's a long time since I used a GT31 Sue, and I don't remember the exact details

It was the upgrade to the GT11

I didn't realise Locosys made the GT31. How could they get it so right with the Gt and stuff up with the GW60?

sboardcrazy said..
I didn't realise Locosys made the GT31. How could they get it so right with the Gt and stuff up with the GW60?

Have you never turned your GT31 over?

add to that the buttons that vent when pressed, and the cheap contacts that corrode when that happens. And the lack of battery life for the distance guys
The software is probably better, seeing as how we had an input into it. The GT31's crashed every now and again, and it was either wait severla days for them to discharge or pull them apart and disconnect the battery

Crap service and warranty resolution is the biggest issue